Gelled electrolytes for use in absorptive glass mat valve-regulated lead-acid (AGM VRLA) batteries working under 100% depth of discharge conditions

► We studied gelled electrolytes to use in AGM VRLA batteries working under 100% DoD. ► Gelled electrolytes and veratraldehyde additive suppressed the hydrogen evolution. ► Gel AGM VRLA batteries had better performance than the nongel AGM VRLA batteries. ► Gel AGM VRLA batteries had longer service life than the nongel AGM-VRLA batteries. ► Adding veratraldehyde additive further improved the battery performance.